How can I automatically let vertices join in a block shape?
I am guessing you have a modifier stack like below:

Make sure Merge is not selected in Array modifier.  Also note that I created a small gap between array elements (using an offset of 1.100), but if Merge is not enabled gap should not be necesary.
Separating Each Block

You need to apply the modifiers, first Array then Curve. (order is important)
Now you have a single mesh containing all the blocks.
Go into Edit Mode.
Choose Mesh -&gt; Separate -&gt; By Loose Parts in menu.
Now you should have each block as a separate object.